Brake shoe



March 6, 1934. w H w|NTER$ 1,949,670

BRAKE SHOE Filed NOV. 2, 1932 INVENTOR ATTORNEY Patented Mar. 6, 1934 UNITED STATES PATENT OFFICE BRAKE SHOE ware Application November 2, 1932, Serial No. 640,838

1 Claim.

This invention relates to brake shoes and more particularly to the limit of wear mark thereon. It has been the practice heretofore to provide a longitudinal rib which projects outward from 5 the side of a brake shoe at the back thereof and midway between its ends to indicate the limit of wear of the shoe. On a flanged shoe this rib is located on the side opposite the flange which is the outer side of the shoe in use; on an unflanged shoe it is located on both sides of the shoe because such shoes are reversible end for end. When a car inspector notes that the body of the shoe is worn down to the limit of wear mark it is his duty to order the shoe replaced. Sometimes the entire body of the shoe from side to side does not wear down in service and a part of the body remains in the form of a flange on the outer side of the shoe so that the inspector may be deceived by the appearance of this flange and think that the shoe is still in serviceable condition when, as a matter of fact, it may have reached the limit of wear. The formation of this flange may be due to improper alinement of the shoe with the wheel and this may result from disarrangement of the brake beam, the head or other causes; and it may also be due to the fact that the shoe is wider than the wheel or the tread of the wheel with which it engages.

The object of my invention is to provide a brake shoe having a limit of wear mark displayed thereon so that it will indicate that the body has been worn to the limit of wear even though a flange remains on the body at the side where the limit of wear mark appears.

In the accompanying drawing I have selected a flanged brake shoe to illustrate the invention and referring thereto Fig. 1 is a perspective view of the shoe,

Fig. 2 is a transverse sectional view, and

Fig. 3 is a fragmentary sectional view on the line 33 of Fig. 2.

Referring to the drawing, the shoe body 3 is provided with a recess 4 in its side which terminates short of the back of the shoe and leaves a rib 5 extending across the recess at the back of the shoe and flush with the surface of the side. This rib constitutes the limit of wear mark and is of a width in the direction from front to back of the shoe suitable for the purpose. The recess may be of any width desired in a direction from end to end of the shoe and it is of a depth equal to the thickness of the average flange which in practice it has been found may be formed on this side of the shoe.

If the shoe is suspended for use with its outer side flush with or inside of the outer side of the wheel the body of the shoe will wear through its outer side, including the recess, and the progress of wear will be observable Without any difllculty. When it is noted that the body has worn down to the rib 5 it will be known that it has reached its limit of wear. If the shoe is so suspended or if it is so wide that the outer side of the body projects beyond the outer side of the wheel a flange will be formed on the body at the outer side thereof because it does not contact with the wheel but this flange will not ordinarily be as wide as the recess in the body and the progress of wear may be noted at the recess. When the body wears down to the rib 5 it will be readily observable even though there may be a flange remaining on the body at each side of the recess and this condition will indicate that the shoe has reached its limit of wear.

I claim:

A brake shoe comprising a body having a back and a side, there being a recess in the side of the shoe spaced from the back of the shoe and providing a rib between the top of the recess and the back of the shoe forming a limit of wear mark, said recess being of sufficient depth in the body of the shoe to disclose the progress of wear of the body if in wearing a flange of less thickness than the depth of the recess remains at the side of the shoe.

WILBUR H. WINTERS. 

